1. Field of the Invention
The present invention relates to a quick connector, for example, to be adapted for assembly in piping of an automobile.
2. Description of the Related Art
In a fluid piping system where a pipe and a hose are connected, a connector is used for connecting the pipe and the hose. In such piping system, the connector has a tubular connector housing including a connector portion at one axial end to be connected to the hose. And, for example, the pipe includes an inserting end portion on an inserting end thereof wherein an annular engagement projection is formed on and around an outer peripheral surface, retainer means is provided at the other axial end of the connector housing for snap-engagement, and thereby the connector is configured as quick connection type. Then, the inserting end portion of the pipe is inserted into an opening on an end of the connector housing so that the annular engagement projection snap-engages with the retainer means to provide locking relation between the pipe and the connector, thereby connection of the pipe and the connector is completed. In retainer means to be adapted for a connector of quick connecting type, namely a quick connector, such wire retainer (for example, a retainer formed from wire member) is often used as to be of U-shape or generally U-shape and have a pair of engaging arms. Here, a pair of engagement slits are formed in a connector housing at the other axial end in diametrically opposed relation, and the wire retainer is mounted on the other axial end of the connector housing or an outer periphery of the connector housing at the other axial end, starting from leading ends of the pair of the engaging arms, so that the engaging arms seat in the engagement slits so as to clip the connector housing (for example, refer to Patent Document 1). Application of such retainer means secures sufficient stability in mounting of a retainer to a connector housing even when a connector is sized relatively large in diameter.
[Patent Document 1] JP-A 2003-21287
By the way, in such type of a connector, the pipe is inserted in the connector housing without play in an axial direction in locking relation, and stable connection between the connector and the pipe is secured. For this purpose, a width of the engaging slit is designed generally equal to a diameter of the engaging arm. However, when the width of the engaging slit is designed equal to the diameter of the engaging arm, a great resistance to sliding movement is exerted by the engaging slits to the engaging arms of the wire retainer while the engaging arms close so as to engage with the annular engaging projection of the pipe, and snap-closing motion of the engaging arms becomes slow. As a result, there is fear that an operator cannot easily judge complete connection between the pipe and the connector. In case that the operator does not find complete connection therebetween, the operator repeats relative insertion of the pipe in the connector housing, and promptness is lowered in connecting work for piping.
And, the wire retainer which is mounted to the connector housing has to be retained in a mounted position for snap-engaging with the annular engaging projection of the pipe. Thus, the wire retainer is configured such that each engaging arm is bent over or inclined radially inward, for example, at a leading end thereof to define an engaging portion, and the engaging portion engages with an outer peripheral surface of the connector housing in a pull-out direction when the wire retainer is mounted to the connector housing.
In a configuration of such quick connector, the wire retainer is allowed to move in the pull-out direction when pulled in the pull-out direction. However, once the wire retainer dismounts from the connector housing, there is no stop or locking function with respect to the pipe. So, a stop portion is formed on the connector housing. In this configuration, when each of the leading end portions of the engaging arms or engaging portions engages with the stop portion in the pull-out direction, the wire retainer is not allowed to move further in the pull-out direction.
This configuration prevents dismounting of the wire retainer from the connector housing. However, when the wire retainer is moved in the pull-out direction, as the leading end portions (at least leading end portions) of the engaging portions slide over the outer peripheral surface of the connector housing, the pair of the engaging arms open, spread apart or move mutually apart gradually. So, it can happen that an external force is exerted to the wire retainer in use, the wire retainer moves in the pull-out direction, the pair of the engaging arms loose a stop or locking function with respect to the pipe, and thereby the pipe is disconnected from the quick connector.
Accordingly, it is an object of the present invention to provide a quick connector having a wire retainer with which a prompt connecting work for piping can be secured without particularly adversely affecting stable connection between the pipe and the connector. And, in one aspect of the present invention, it is an object to provide a quick connector also having a configuration that does not cause incomplete connection with the pipe during use.